seized front sprocket.

[v8legend]

I'd agree with that ... G

Shouldn't your rear sprocket have worn quicker than the front? They usually do.

 

[rce]

The front sprocket is subject to much more wear, each tooth will be meshing with the chain for approx 2.5x more than what a rear tooth does.

 

[Dave Ett]

Tolerances these days will be pretty much consistent I'd imagine ...

Dave - had yours ever been off before? I can only guess that if it had been, then it might have been reassembled with a little lube - mine was as dry as a nun's ... ooops! no no - as dry as a bone... as was evidenced by the puff of rust powder when it finally let go...

We all know that a little lubrication goes a long way!

G

Dunno, I bought the bike with 8500 miles on the clock. It did have a DID fitted, so possibly...

As for tolerances, I was thinking of the cheap manufacturer used for the chain / sprockets (hence all the failures) and wondering if their QC was as rubbish as the materials they used...

 

[Greggers]

Yes I understand that, but in all honesty both sprockets were bearing up relatively well - the pictures tell all I think ...

I'll see how the Izumi stands up - hopefully I'll get more than the 10k I got from the 'Iris' chain I bought last year... I'll be turning the Scottoiler up I think

G

 

[Dave Ett]

Only 10k? Strewth! Have you done a lot of off-roading?

 

[Greggers]

Not really - but I guess if you spend £50 on a chain it's just not going to last...

 

[v8legend]

The front sprocket is subject to much more wear, each tooth will be meshing with the chain for approx 2.5x more than what a rear tooth does.

I hear what you're saying, and it makes sense. But from experience (when I worked in a bike shop), the rears wear much quicker. I think it's because they're exposed to the elements. Whereas the front is well protected.

 

[Greggers]

I hear what you're saying, and it makes sense. But from experience (when I worked in a bike shop), the rears wear much quicker. I think it's because they're exposed to the elements. Whereas the front is well protected.

The ratio of 'work' that the front does compared to the rear is much much higher. The front sprocket is subject to much greater torque than the rear, and has a much smaller surface area through which to transfer it (via the chain) to the rear wheel. In my example, neither sprocket is showing significant wear, but the front is starting to hook as a result of the torsional stresses it's subjected to.

As a rule the materials from which these chain wheels are produced is different, with rears made from heat treated pressed steel, and fronts made with powder metallurgy (google it..,lol) which makes for a much harder, denser and work resistant steel...

G

 

[v8legend]

Ahhh ok then ...

I'm doing something for the local BMWOC 'chapter' in October ...

How does mid November sound? Good time to test the thermal undies!!

G

When exactly is mid November?